US1691096A - Railway-traffic-controlling apparatus - Google Patents

Description

Noir. 13, 1928.

H. A. WALLACE RAILWAY TRAFFIC CONTROLLING APPARATUS Fild oct. 2o, 1925 2 sheets-Sheet 2 via N Patented Nov. t3, 1928,

'iran STATES PATENT oFFics.

` HERBERT A. WALLACE, oF Enenwcon, PENNSYLVANIA, AssreNoR To THE UNION BWITGH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION F PENNSYLVANIA.

BAILWAY-TRAFFIC-CONTROLLING APPARATUS.

My invention relates to railway traic controlling apparatus, and particularly to apparatus of the type comprising governing mechanism on a train controlled by energy received from t-he trackway.

I will describe two forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic View showing one form and arrangement of apparatus adapted tobe carried on a train and embodying my invention. Fig. 2 is a view showing a modification of a portion of the apparatus illustrated in Fig. 1 and also embodying my invention. Fig. 3 is a diagrammatic View showing' one form and arrangement of trackway apparatus for coopertion with the train carried apparatus illustrated in Figs. 1 and 2. Similar reference characters refer to similar parts in each of the several views.

Referring first to Fig. 3, the reference characters l and ladesignate the track rails of a railroad over which traic normally moves in the direction indicated by the arrow. These rails are divided, by means of insulated joints 2, into a plurality of successive track sections A-eB, B-C, etc. The portionof track to the left of point C is provided with trackway apparatus for positively maintaining the automat-ic brake application apparatus on the train in an inoperative condition by means of energy supplied to the train from the trackway through the lmedium of recciving appliances which I will describe in detail hereinafter. This portion of track I will therefore hereinafter term control territory, and the portion of the track to the right of point C which is not equipped with such apparatus, l will hereinafter term neutral territory.

ln the control territory, each track section is provided with a track relay designated by reference character R with an exponent corresponding to the location and connected across the rails adjacent the entrance end of the section. As here shown each such relay is responsive to direct current. Each track section is also provided with a source of uni-directional track circuit current such as a battery 10, and a source of alternating track circuit zur-rent such a trackitransformer here designated by the reference character T with an eX- ponent corresponding to the location. A trackf battery l0 and the secondary 8 ot' a track transformer T are connected in series across the rails adjacent the exit end of each section. It is therefore clear that each track section is provided with a track circuit including a track relay R, a battery 10, the secondary 8 of a tra-ck transformer 10 and the two rails 1 and 1 of the section in series.

he primary 9 of each track transformer in the control territory 'is at times supplied with alternating current over a circuit controlled by a front contact of the track relay associated with the section next in advance. Referring particularly to transformer TB, a circuit passes from a suitable source of alterhating current such as an alternator D, through line Wire 17, wire 18, front contact 11 of track relay RB, wire 19, primary 9 of transformer TB, wire and line wire 17a back to alternator D. It will be plain from the foregoing that each track section is constantly supplied with direct track circuit current and that each section is further provided with alternating track circuit current when the track relay for the section neXt in advance is energized, that is, when such latter section is not occupied by a train.

Each section is further provided with an auxiliary transformer designated by the reference character L with a suitable exponent and located adjacent the entrance end of the section. The primary 16 of each such transformer L is constantly supplied with alternating current from alternator D over line wires 17 and 17a. A conductor 14 is located in the trackway parallel with and adjacent to one rail 1 near the junction of each two sections. Each suoli conductor 14 is constantly supplied with alternating current from the secondary 15 of the associated auxiliary transformer L.

Adjacent the entrance end of the neutral territory to the right of point C is a transformer K the primary 13 of which is const-antly supplied with alternating current from alternator D over line wires 17 and 17a. The secondary 12 of transformer K is provided with a circuit including, in series, two spaced 41L engages a conductors 21 and 22 arranged adjacent the two track rails 1 and 1, respectively. For reasons Which shall appear hereinafter, the parts are so proportioned that the alternating currenttraversing conductors 21 and 22 is of considerably greater magnitude than the alternating current supplied to the rails of each track section by the associated track transformer T.

Referring now to Fig. 1, the train carried apparatus here shown comprises a receiving appliance which 1 shall refer to collectively as the track coil and which is designated in general by the reference character E. This track coil comprises a pair of magnetizable cores 23 and 23 supported b y the frame of the locomotive in front of the forward axle (not shown in the drawing) and disposed immediately above and transversely with respect to the two track rails 1 and 1, respectively. Core 23 is provided with a winding 24 and core 23a is provided with a similar winding 24, these two windings being connected together so that the voltages induced by alternating currents flowing in opposite directions in the two track rails are additive. The terminals a and b of the track coil are connected, through suitable amplifying apparatus G with the winding of a control relay J. Interposed between terminal a of the track coil and one terminal of the amplifying apparatus is a resistance 25 the purpose ofwhich will be explained in detail hereinafter. A manually operable cut-out switch P is biased by some suitable means? such as gravity, to a position in which its back contacts 26 and 27 are closed, thus closing through wires 28 and 28, a path of low resistance around resistance 25.

Associated with relay J is a slow acting relay S which is at times energized from a suitable source of energy such as a generator N. Associated also with relay J and controlled in part thereby are a magnet valve M and a timing mechanism Q. This timing device may be of any suitable form and is here shown as an electric timing device comprising a rotatable shaft 100 supported by means not shown in the drawing and provided with a contact cam 41 having a projection 41a thereon and rigidly attached to the shaft. Under normal conditions shaft 100 is biased by means of a spring 101 into the position shown in the drawing in which the cam projection Xed stop 106 thus limiting further motion. A motor device is adapted, when energized, to rotate shaft 100 against the bias exerted by spring 101 into a position in which projection 41a is preventedfrom further motion by a contact strip 43 which bears constantly against the edge of cam 41. A friction clutch 40 of any suitable form is interposed between motor device 40' and shaft 100 to permit the motor device 40 to continue to operate after cam 41 has completed its m0- tion. The shaft 100 is also adapted to be moved longitudinally. The reference character 105 designates a rotatable shaft co-axial with shaft 100 and adapted to be rotated by motor device 40. Rigidly attached to shaft 105 is a collar 107. A second collar 103, rotatable on shaft 100 is adapted at times to engage a projection 102 on shaft 100. Two weights 108 are attached by means of linkwork to collars 103 and 107. Under normal conditions shaft 100 is biased to its left hand position by spring 104 but when motor 40 is energized, shaft 105 is rotated. and weights 108 are caused, by centrifugal force, to move away from shaft 105, thus ca'using collar 103 to engage projection 102 and thereby move shaft 100 longitudinally to the right until the end of shaft 100 engages the end of shaft 105 thereby preventing further movement. A contact linger 42 is so disposed that when shaft- 100 is in its right hand position and motor 40 has turned this shaft till projection 41a engages contact 43, projection 41a also engages contact 42. It should be noted that contact 42-41a will be closed only when motor device 40 is actually energized. The parts are so proportioned that following energization of motor device 40, a definite time interval of, for example, seconds elapses before contact 42-41n is closed.

Relay J controls the magnet valve M as follows:

When relay J is energized, magnet M is energized over a circuit which passes from generator N through Wires 29 and 30, front point of contact 31 of relay J, wires 32 and 33, winding of magnet valve M, and wires 34 and 35 back to generator N. If relay J is de-ener gized this circuit is broken, allowing magnet M to become de-energized. The de-energization of relay J also closes the circuit for timlongitudinally fixed,

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ing mechanism Q, and current flows fromA generator N through wires 29 and 30, back point of contact 31 of relay J, wire 36, back point of contact 37 of relay S, wire 38, motor device 40 of timing mechanism Q, and wires 39 and 35 back to generator N. Motor device 40 is therefore energized and at the expiration of the time interval of 60 seconds as explained hereinbefore, a second circuit for magnet M is closed and current then Hows from generator N, through wires 29 and 30, back point of cont-act 31 of relay J, wire 3G, back point of contact 37 of relay S, wires 38 and 45, contact finger 43, cam 41, contact `finger 42, wires 32 and 33, winding of magnet M, and wires 34 and 35 back to generator' N.

The magnet valve M is of the usual and well known pin valve type and comprises a chamber 44 containing a valve stem 46. Vhen magnet M is de-energized, valve stem 46 is moved, by means of a spring 46a, into a position wherein chamber 44 is connected with a chamber 47 which is in turn constantlyl lll) connected with atmosphere through a port 48. vWhen magnet M is energized, valve stem 46 is moved downward `against the bias exerted by spring 46a into a position wherein communications between chambers 44 and 47 is prevented.

An automatic brake application valve W is controlled by the magnet valve M in the following manner: y

The brake application valve 1V comprises a valve body 49 provided with a cylinder 50 containing a reciprocable piston 51. The valve body 49 also comprises a valve chamber 54 containingr a slide valve 52. Fluid pressure is constantly supplied to chamber 54 from some suitable source such as a main reservoir as indicated by the reference characters M. R.. the parts being so disposed 'that such pressure is constantly applied to the right hand side of piston 51. The piston 51 1s provided with a restricted feed port 51a through which Huid pressure is supplied to chamber 50 from chamber 54. Vhen the pressures in chambers 54 and 50 areequal,piston 51 and slide valve 52 operatively7 connected therewith are moved by a spring 53 into their right hand or release position. Chamber 50 is connected by means of pipe 4 with chamber 44 of magnet valve M. It is therefore evident that when valve M is de-energized, chamber 50 of valve `W is vented to atmosphere and piston 51 and slide valve 52 are then moved into their reverse or application positions by the unbalanced fluid pressure on the right hand face of pistoii '51. A brake pipe 8 is normally supplied with fluid pressure from chamber 54 of valve W through pipe 6, a feed valve 64 and a manually operable engineers brake valve U. As is well understood, a reduction in pressure in pipe 3 causes an application of the brakes. The valve body 49 is provided also with a cylinder divided into an upper chamber 58 and a lower chamber 61 by .a reciprocable piston 59. This piston is provided with a stem 59EL adapted for at times closing port 60 which port is connected with atmosphere. The lower chamber 61 is constantly connected with brake pipe 3 andthe upper chamber 58 is constantly connected with a reservoir 55. When valve W is in the release position, an auxiliary reservoir 56 is connected with atmosphere through port 57 and brake pipe 3 is connected with reservoir through ports 62 and 63. Under these conditions it is plain that the same pressure exists in brake pipe 3, reservoir 55, chamber 58 and chamber 61. The area upon which such pressure is effective upon the upper surface of piston 59 is greater than the area upon which such pressure is effective upon the lower surface of this piston by an amount equal to the area of stem 59aL which is exposed to atmosphere'and this unbalanced pressure and the force of gravity combine to move piston 59 downward, thus closing port 60. If, now, valve W is reversed as by de-energization of magnet valve M, reservoir 55 is disconnected from brake pipe Sand reservoir 56 is disconnected from atmosphere. Reservoir 56 is subsequently connected with reservoir o5. As a result the pressure in reservoir 55 and hence in chamber 58 is reduced by an amount which is dependent upon the ratio of the two reservoirs. As brake pipe pressure still exists in chamber, 61, piston 59 is moved upward, due to the decreased pressure above the piston, thus opening port 60. Brake pipe pressure is thereby dissipated to atmosphere through port 60 until reduced to such a value that the pressure above piston 59 forces the piston downward and prevents further reduction in brake pipe pressure. This reduction in brake pipe pressure causes the brakes to be applied, and the brake pipe can not be supplied with fluid pressure through valves 64 and U since pipe 6 is disconnected from chamber 54 by the reversal of valve W. When valve W is in the reverse position chamber 50 is connected with atmosphere through port 65, pipe 5, engineer-s valve U and port 66. This pipe can be closed from atmosphere only by moving valve U to the lap position. if magnet valve M is energized, and valve U is in the lap position, pressure admitted to chamber 50 through port 515L builds up till the spring 53 moves slide valve 52 into the release position. The brakes can then be released by moving valve U to the release position to supply fluid preissure to brake pipe 3. It will be clear then that followingan .automatic brake application resulting from venting of chamber 50 of valve W to atmosphere by valve. M. the brakes can subsequently be released only when valve M is closed and then only by deliberate manipulation of valve U by the engineman who must first move valve U to the lap position and` then to the release position.

Referring also now to Fig. 3, I will assume that a train occupies section B-C. As a result,relay RB is cle-energized, thus disconnecting the primary 9 of track transformer TB from its energy source and hence interrupting the supply of alternating track circuit current to the rails of section A B. This, however, does not aifect the supply of direct current to this section and relay RA is therefore energized and the section to the left of point A. is supplied with both altern ating and direct track circuit currents. I will also assume that a second train, provided with apparatus thus far explained in connection with Fig. 1 passes through the stretch of track shown in the drawing. As this train passes through the section to the left of point A, the alternating current in the rails induces in track coil E an electromotive force which is effective to energize relay J .Under these conditions magnet M is energized and the brakes are released. As the track coils move over conductor 14 at point A the apparatus is not affected since the electromotive force induced in the coil by -current invthis conductor tends to energize relay J which is already in its energized condition. After the train passes conductor 14, however, the cessation of alternating track circuit current iu section A-B allows relay J to become cle-energized, thus Cle-energizing magnet valve M and causing lan automatic brake application as hereinbefore explained. Simultaneously` the timing mechanism Q is energized, and after the exiration of time required'for its operation,

in this case 60 seconds, contact 42-41-43' again closes the circuit for magnetM, and the brakes can then be released by proper manipulation of the engineer-s valve U. As the train passes point B, however thel relay J is again energized as the track coil passes over conductor 14 and is again de-energized after the train has passed this conductor. The brief interval of time during which relay J is ener- `gized, is suficient to allow timing device Q to return to its normal position andthe subsequent de-energization of relay J, therefore causes the brakes to be again applied.

It is evident that as the train pass-cs from controlled territory to neutral territory the absence of alternating track circuit current i u the neutral territory, in the absence of preventative means will result in the application of the brakes in the manner just described in connection with movements of a train into a section of track in controlled territory which section is deprived of alternating track circuit current by a train occupying the section in advance. This is undesirable and to prevent its occurrence I have provided on the train certain apparatus adapted to co-operate with the lcircuit 21, 22 located at the entrance end of such neutral territory.

1f cut-out switch P is moved upward the opening of contacts 26 and 27 thereon opens the low resistance shunt around resistance 25. The resulting decrease in the current through relay J will cause this relay to become de-energizcd if the track coil is over a stretch of track supplied with alternating track circuit current of normal value or'if the track coil is over one of the conductors 14. 1f however, the track coil is over the circuit 21, 22, the large current in these conductors will cause relay J to become energized even though cut-out switch P is in its upper position. Under these circumstances relay S is energized over a circuit which passes from generator N, through wires 29, 30 and 67, winding of relay S, wires 68 and 69, front point of contact 70 of relay J, wire 71, contact 72-73 of cut-out switch P, and wires 74 and 35 back to generator N. When the track coil passes off of circuit 21, 22, relay J becomes de-energized. The engineer then allows cut-out switch P to return to its normal position, thus closing a retaining or stick circuit for relay S passing from generator N, through wires 29,30 and 67., winding of relay S, Wires 68 and 7 5', front point of contact 75 of relay S, wirc 7G, back point of contact 77 of relay J, wire 78, back contacts 79-80 of cut-out switch P and wires 74 and 35 back t0 generator N. Under these conditions it is apparent that relay S will be maintained in its energized condition while the train passes through neutral territory, but that when the train again enters control'territory, the energization of relay J opens the stick circuit just traced and restores the apparatus to normal by de-energization of relay S. When \relay S is energized, however, magnet valve M is energized over a circuit which passes from generator N, through ` wires 29 and 30, front point of contact 8l of relay S, wires 82, 32 and 33, winding of magnet M` and wires 34 and 35, back to generator N. Relay S is preferably slow acting to prevent it from releasing during the possible short interval between the opening of its pick-up circuit and the closing of its stick circuit.

In explaining the operation of the apparatus as a whole I will first assume that section B-C of the portion of track shown in Fig. 3 is occupied by a train. If, now, a train provided with the apparatus illustrated in Fig. 1 enters the stretch of track shown in Fig. 3, the relay J is de-energized as the train passes beyond conductor 14 at point A. and the brakes are thereupon applied'by the deenergization of magnet valve M. At the same time timing mechanism Q, is energized and after the expiration of the time interval required for its operation, magnet valve M is again energized. After Valve M is again energized the brakes may be released by proper manipulation of the engineers valve U. The train is then allowed to proceed without restriction as far as point B where the temporary energization of relay J by the co-operation of the track coil E with conductor 14 allows timing mechanism Q to return to its normal condition. The subsequent deenergization of relay J as the track coil E passes out of inductive relation with conductor 14 results in de-energization of magnet M and hence in a second brake application.

It is therefore plain that the brakes on the train are applied as the train enters a section in rear of an occupied section, that the brakes may subsequently be released only at the expiration of a definite predetermined time interval, and then only by deliberate action of the engineer, and that the brakes are again applied as the train enters the occupied section and may be released in the same manner as before.

I will now assume that the section of track shown in Fig. 3 is unoccupied and that a train moves through this stretch in the direction indicated by the arrow. If cut-out switch P is not operated properly as the train passes into the neutral territory to the right of point C the resulting de-energization of relay J will cause an automatic brake application in exactly the same manner as when thctrain enters the section in rear ot an occupied section.

1f, however, just prior to the exit of the train from the control territory, the engineer moves cut-out switch P into its upper position, relay J is de-energized momentarily, but is re-encrgized when the track coil passes over circuit 2l 22, thus closing the circuit for magnet M? through front contact 31 thereon and also the. pick-up circuit for relay S. As the track coil passes out of inductive relation with the conductors 21 and 22, relay J becomes cle-energized, thus closing its back contact 77. Ylhe engineer then allows cutout switch l? to return to its normal position, thereby closing the stick circuit for relay S. It will be noticed that when relay S is energized and relay J becomes tie-energized, timing device Q is not energized, its circuit heilig open at back contact 37 ot relay S. llt will be clear from the foregoing that manipulation of cut-out switch P as the train leaves controlled territory will prevent an automatic brake appli cation which would result in the absence of such manipulation., i

After such cutting out the automatic brake application apparatus remains ineti'ective until the train again enters a stretch ot track supplied with alternating track circuit current or passes a conductor 14. j

An indicator H is mounted in the locomotive cab or other suitable place and connectech in multiple with the magnet M to inform the engineer concerning the condition of energization of this magnet.

Referring now to Fig. 2, the magnet valve M, here shown symbolically controls a brake application valve in exactly the same manner as illustrated in Fig. 1. 1n Fig. 2 when relay J is energized, magnet valve M is enervized over a circuit whichis the same as that shown in Fig. 1. lVhen relay J is de-energized, this circuit is broken', thus allowing magnet M to apply the brakes, and at the same time a circuit is closed for motor 40 of timing device Q and current iiows from generator N through wiresv 29 and 30, back point of contact 31 of relay J, wire 83, contacts 84-85 of cut-out switch P, wire 86, back contact 37 of relay S, wires 38 and 45, motor device 40 of timing mechanism Q and wires\ 39 and 35 back to generator N. The timing device Q, after a definite time interval as in Fig. 1, completes the circuit from contact finger 42 to contact linger 43 through cam 41 and thereby closes a circuit which passes from generator N through wires 29 and 30, back point of contact 31 of relay J, wire 83, contacts 84 and 85 of cut-out switch l), wire 86, back contact 37 of relay S, wire 38, contact linger 43, cam 41, contact finger 42, wires 32 and 33, winding of magnet M, and wires 34 and 35 back to genneutral territory is as lollows:

era-tor N. ,It will thus be clear that following de-energization of relay J, the brakes will be applied for a time interval at the expiration of which the operation of timing mechanism Q energizes magnet valve M and allows the brakes to be manually released by the engineer.

'I he operation of the apparatus when the train 1s passing from controlled territory to The engineer moves cut-out switch l) into its upper positlon just prior to the exit oit the train from controlled territory. As a result, the low resistance shunt around resistance is broken at contacts 26-27 on cut-out switch l?. Resistance 25 is therefore connected directly in series with the amplifying apparatus and relay J is therefore de-energized. This operation closes a circuit. which passes from generator N, through wires 29 and 30, back point of contact- 31, of relay J, wire 83, contacts 87-88 et' cut-out switch P, wire 89, contact finger 90, cam 41, contact linger 43, wire 45, motor device 40 otl timing device Q, and wires 39 and 35 back to generator N. The timing device Q is provided with ay second cont-act cam 82 provided with a projection adapted to at times engage a contact finger 93. A second contact finger 94 constantly engages the cam 82. 'l` he parts are so disposed that when motor device 40 is energized over the circuit just traced, it operates to move the cams 82 and 41 iu a counter-clockwise direction, thus causing projection 82a to engage finger 93. Continued motion of cam 41 in the same direction causes linger 90 to disengage projection 41 and current is thereafter supplied to motor device 40 from wire 89, through resistance 91, to Wire 38 as before. The value of resistance 91 is such that under the con ditions described above, that is, after motor device 40 has moved projection 41a out of engagement with contact finger 9() power is supplied to this device in such amount as to ust counteract the frictional force exerted on this motor by the timing device Q and thus cause the apparat-us to iioat in a position wherein contact finger 93 engages cam projection 82a. It relay J is now energized, as by moving oi' track coil E into inductive relation with circuit 2l., 22, a circuit is closed which passes from generator N, through wires 29, 30 and 67, winding of relay S, wires G8 and 69,.t`ront point 01:' co`ntact 70 of relay J, wire 71, contacts 72 and 73 of con-K tact switch P, wire 92, contact finger 93, cam 82, contact finger 94, and wires 95 and 35 back togenerator N. Slow acting relay S is thereupon energized. As the relay J becomes deenergized, following the moving of track coil E out of inductive relation with circuit 21, 22, a. stick or retaining circuit for slow acting relay S is closed and current flows `from venerator N, through wires 29, 30 and 67, w1nding of relay S, wires 68 and 75, front point ffl) of contact of relay S, wire 76, back point of contact 77 of relay J', and wires 78 and 35 back to generator N. If cut-out switch P is now released, a circuit is closed for magnet M over which current flows from generator N, through Wires 29 and 30, front point ot contact 8l of relay S, Wire 96, contacts 97 and 98 of cut-out switch P, Wires 99, 32 and 33, winding of magnet valve M, and Wires 34 and 35 back to generator N. It will thus be clear that if the apparatus is operated in this manner the train will be allowed to proceed into neutral territory without a brake application.

The operation of the apparatus as a train moves through the ortion of track shown in Fig. 3 will be readlily understood from the foregoing without further explanation.

It should be particularly pointed out that with the apparatus shown in Fig. 2, since the pick-up circuit for relay S includes contact inger 93 and cam 82, relay S cannot be picked up by operation of cut-out switch P unless relay J is properly energized, that is, by current induced in the track coil by current in circuit 21, 22.

Although I have herein shown and described only two forms of railway trafiic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway traiic controlling apparatus comprising automatic uid pressure braking mechanism on a train, means responsive to traic conditions in advance for at times actuating said mechanism, and slow acting means including an electric motor for subsequently preventing such mechanism from being manually restored to its normal condition for a given time interval.

2. In combination with an automatic fluid pressure braking, mechanism on a train, a normally energized relay, means responsive to traffic conditions in advancefor at times de-energizing said relay, means for subsequently temporarily re-energizing said relay, a magnet valve controlled by such relay for actuating said mechanism, and a timing device also controlled by said relay and including an electric motor and operating to prevent release of said braking mechanism for a given interval of time after operation of said mechanism.

3. In combination with an automatic fluid pressure braking mechanism on a train, a relay responsive to traic conditions in advance, a slow acting relay controlled by said irst rela a timing device also controlled by said rst relay and including an electric motor, a magnet valve controlled by said slow acting relay and said timin device, and means controlled by said valve or actuating said mechanism.

- 4. In combination with an automatic liuid pressure braking mechanism on a train, a relay responsive to trame conditions in advance, a normally energized magnet valve, means controlled by said valve for actuating said'mechanism, means incorporated in said relay for at times de-energizmg said valve, and means including an electric motor for subsequently preventin said valve from becommg re-energized or a given interval of time.

5. In combination with an automatic :fluid pressure braking mechanism on a train, relay responsive to traiic conditions in ad vance, means controlled by said relay for actuating lsaid mechanism, and means including an electric motor for subsequently preventing said mechanism from being restored to its normal condition for a given interval of time.

6. In combination with an automatic fluid brake application mechanism on a train, means controlled by trac conditions in advance for at times actuating said mechanism to apply the brakes, manually operable means for restoring said mechanism to its normal condition, and timing means including an electric motor for preventing said mechanism from being restored to its normal condition for a given interval of time.

7. In combination with an automatic iuid pressure brake application mechanism, a relay responsive to traiiic conditions in advance, a magnet valve adapted when deenergized to actuate said mechanism to apply the brakes, a circuit for said magnet valve including a source of energy and a front contact on said relay, a normally open Contact adapted to be closed after a time interval following the de-energization of said relay; and a second circuit for said magnet valve including a source of energy, a back contact of said relay and said contact.

8. In combination with an automatic fluid pressure brake application mechanism, a relay responsive to traiiic conditions in advance, a magnet valve adapted when de-energized to actuate said mechanism to apply the brakes, a circuit for said magnet valve including a `source of energy and a front contact on said relay, a motor device controlled by said relay, a cam controlled by said device, a contact finger constantly engaging said cam, a second contact nger adapted to engage said cam after the expiration of a time interval following de-energization of said relay, and a second circuit for said magnet valve including a source of energy, a back contact of said relay, and said two contact lingers.

9. In a railway traiiic controlling system comprising a stretch of track divided into consecutive sections, means responsive .to traffic conditions in advance for supplying the rails of each section with alternating track circuit current, an auxiliary conductor located in the trackway adjacent one end of each of said sections, and means for constantly supplying such conductor with alternat ing current; the combination with the aforementioned instrumentalities of an automatic fluid pressure brake applying mechanism on a train, means responsive to the presence or absence of' alternating current in the trackway, an electro-responsive timing device controlled by said means and including an electric motor, and means controlled by said device for actuating said mechanism.

l0. In combination with an automatic fluid pressure brake application mechanism, a motor device responsive to traflic conditions in advance, a cam operated by said motor device, a relay on the train adapted to be energized when that portion of trackway occupied by the train is supplied with alternating current, means controlled by said relay for actuating said mechanism to apply the brakes, and means controlled by said cam for permitting such mechanism to be manually restored to its normal condition.

l1. In combination with an automatic fluid pressure brake applying mechanism on a train, a manually operable switch having a normally open contact and a normally closed contact, a relay controlled by said switch and responsive to traffic conditions in advance, a second relay, a pick-up circuit for said second relay including a contact of' said first relay and said normally open contact, a stick circuit for said second relay including a eontact of' said first relay and said normally closed contact, and means controlled'by said second relay for actuating` said mechanism.

12. In combination with an automatic fluid pressure brake applying mechanism on a train, a manually operable switch having anormally open contact and a normally closed contact, a relay controlled by said switch and respon# sive to trafc conditions in advance, a second relay, a pick-up circuit for said second relay including` a contact of said first relay and said normally open contact, a stick circuit for said second relay including a contact of said first relay and said normally closed con* tact, a magnet valve controlled by said second relay, and means controlled by said magnet valve for actuating said mechanism.

13. In combination with an automatic fluid pressure brake applying mechanism, a relay responsive to trafc conditions in advance, an electro-responsive timing device, an auxiliary relay, a manually operable switch, a circuit for said timing device including a back contact ori said-first relay an'd a back contact on said auxiliary relay, a pick-up circuit :tor said auxiliary relay including a front contact on said first relay and a normally openrcontact on said switchja stick circuit for said auxiliary relay including a front contact on said auxiliary relay, a back contact on said first relay, and a normally closed contact on said switch; means controlled also by said switch for modifying the control of' said first relay, a magnet valve, a circuit for said magnet valve including a front contact on said first relay, a second circuit f'or said magnet valve including a front Contact on said auxiliary relay; a third circuit f'or said magnet valve including a back contact on said first relay, a back contact on said auxiliary relay, and a contact on said timing device, and means controlled by said magnet valve for actuating said mechanism.

14. In combination with an automatic fluid pressure brake applying mechanism on a train, a relay responsive to traffic conditions in advance of the train, a manually opcrable switch, means controlled by said rc lay for actuating said mechanism to apply the brakes, lneans for restoring said mecha` nism to its normal condition, and timing means controlled by said switch and by said relay for preventing said mechanism from being restored to its normal condition for a given interval of time.

l5. In combination with an automatic fluid pressure brake applying mechanism on a train, a relay responsive to trafiic conditions in advance of the train, a manually operable switch comprising a normally open contact, a timing device, a circuit for said timing device including said normally open contact, a normally open contact on said timing device adapted to be closed at the end of a time interval after the closing of said circuit, an auxiliary relay, a circuit for said relay including said contact on the timing device, and means controlled by said auxiliary relay for actuating said mechanism.

16. In combination with an automatic fluid pressure brake applying mechanism on a train, a relay responsive to traflic conditions in advance of the train, a timing device comprising a motor device, a circuit for said motor controlled by said relay, a contact on said timing device adapted to be closed at the expiration of a time interval after the closing of said circuit, a second contact on said timing device adapted to be closed after the expiration of a different fixed time interval after the closing of said circuit, an auxiliary relay controlled by said first contact, and means controlled by said relay and said second contact for actuating said mechanism. 17. In combination with an automatic fluid pressure brake applying mechanism on a train, a relay responsive to traffic conditions in advance of the train, a timing device controlled by said relay, means controlled by said relay for operating said device, means for subsequently interrupting such operation prior to the completion thereof, a second relay I controlled by said timing device, and means said second contact, a manually operable switch, an auxiliary relay controlled by said switch and said tirst contact, and means controlled by said auxiliary relay for actuating said mechanism.

19. In combination with an automatic fluid pressure brake applying mechanism on a train, a relay responsive to trafiic conditions in advance or' the train, a timing device comprising a contact adapted to be closed at the expiration ot' a time interval after the ener* gization of said device and a second. contact adapted to be closed at the expiration ot a different time interval after the energization of said device, means controlled by said relay for closing said first contact but not said second Contact, a manually operable switch, an

means controlledby said second contact for actuating said mechanism.

20. Incombination with an automatic fluid pressure braking mechanism on a train, means responsive to traiiic conditions in advance for setting said mechanism into operation to apply the brakes, means responsive to manipulation of the engineers brake valve for subsequently releasing the brakes, and means including an .electric motor for preventing release of the brakes for a given interval oi' time following an automatic application of the brakes.

21. In combination with a fluid pressure braking system on a train, a magnet normally energized but de-energized under unsafe traflic conditions in advance, means for causing an automatic application of the brakes when said magnet'becomes de-energized, slow-acting means including an electric motor for subsequently re-energizing said magnet, and means responsive to manipulation of the engineers brake valve for releasing the brakes if and only it' said magnet is energized.

In testimony whereof I aflix my signature.

HERBERT A. WALLACE.

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